Dataset Information

Influence of fixation on CA4+ contrast enhanced microCT of articular cartilage and subsequent feasibility for histological evaluation.

ABSTRACT: CA4+ is a novel cationic iodinated contrast agent utilized for contrast-enhanced microCT (CECT). In this study, we compared CA4+ CECT for cartilage quantification of unfixed and neutral buffered formalin (NBF)-fixed rabbit distal femur cartilage after 8-, 24- and 30-hours of contrast agent diffusion. The stability of CA4+ binding to cartilage after PBS soak and decalcification was also investigated by CECT. We further assessed the feasibility of cartilage histology and immunohistochemistry after CA4+ CECT. Contrast-enhanced CA4+ labeled unfixed and NBF-fixed cartilage tissues facilitate articular cartilage quantification and accurate morphological assessment. The NBF fixed tissues demonstrate higher cartilage intensity and imaging characteristics distinct from subchondral bone than unfixed tissues while maintaining stable binding even after decalcification with 10% EDTA. The unfixed tissues labeled with CA4+, after CECT imaging and decalcification, are amenable to H&E, Alcian blue, and Safranin O staining, as well as Col2 immunohistochemistry. In contrast, only H&E and Alcian blue staining can be accomplished with CA4+ labeled NBF fixed cartilage, and CA4+ labeling interferes with downstream immunohistochemistry and Safranin O staining, likely due to its positive charge. In conclusion, CA4+ CECT of NBF fixed tissues provides high quality microCT cartilage images and allows for convenient quantification along with feasible downstream H&E and Alcian blue staining after decalcification. CA4+ CECT of unfixed tissues enables researchers to obtain both quantitative microCT as well as cartilage histology and immunohistochemistry data from one set of animals in a cost-, time-, and labor-efficient manner.

SUBMITTER: Gao X

PROVIDER: S-EPMC8430171 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Articular cartilage lines the load-bearing surfaces of long bones and undergoes compositional and structural degeneration during osteoarthritis progression. Contrast enhanced microcomputed tomography (?CT) is being applied to a variety of preclinical models, including the mouse, to map structural and compositional properties in 3-D. The thinness (?30-50??m) and high cellularity of mouse articular cartilage presents a significant imaging challenge. Our group previously showed that mouse articular cartilage and proteoglycan (PG) content can be assessed by ?CT with the ioxagalate-based contrast agent Hexabrix, but the voxel size used (6??m) was deemed to be barely adequate. The objective of the present study is to assess the utility of a novel contrast agent, CA4+, to quantify mouse articular cartilage morphology and composition with high resolution ?CT imaging (3??m voxels) and to compare the sensitivity of CA4+ and Hexabrix to detect between-group differences. While both contrast agents are iodine-based, Hexabrix is anionic and CA4+ is cationic so they interact differently with negatively charged PGs. With CA4+, a strong correlation was found between non-calcified articular cartilage thickness measurements made with histology and ?CT (R2 ?=?0.72, p?<?0.001). Cartilage degeneration-as assessed by loss in volume, thickness, and PG content-was observed in 34-week-old mice when compared to both 7- and 12-week-old mice. High measurement precision was observed with CA4+, with the coefficient of variation after repositioning and re-imaging samples equaling 2.8%, 4.5%, 7.4% and 5.9% for attenuation, thickness, volume, and PG content, respectively. Use of CA4+ allowed increased sensitivity for assessing PG content compared to Hexabrix, but had no advantage for measurement of cartilage thickness or volume. This improvement in imaging should prove useful in preclinical studies of cartilage degeneration and regeneration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2740-2748, 2017.

Project description:Purpose:Arthroscopic surgery has become an important and popular orthopedic procedure for numerous joint disorders. Continuous irrigation is performed to replace synovial fluid for optimal joint distension and clear visualization of the synovial cavity. Irrigation solutions may, however, negatively impact articular cartilage and chondrocyte viability. This systematic review aims to compare different irrigating solutions and their properties to determine whether one is superior in its effects on articular cartilage and chondrocytes. Methods:A systematic literature review was conducted. The online databases: Embase, Medline, HealthStar, Emcare and PubMed were searched from 1946 to August 2018. Methodological index for non-randomized studies (MINORS) was used to assess methodological quality of the included studies. Results:Sixteen studies met the inclusion/exclusion criteria and were included in this review. Although the studies used different criteria to define superiority, solution superiority was based on results that focused on articular cartilage and chondrocyte viability. Seven of the sixteen included studies compared Ringer's/lactate solution or Ringer's lactate to normal saline. Three found Ringer's solution or Ringer's lactate to be superior to saline, whereas, three studies found no significant differences and one study found Ringer's lactate to be inferior to saline only when their osmolarities differed. Four studies compared ionic to non-ionic solutions. Two of the four studies demonstrated non-ionic solutions to be superior, one had demonstrated no significant differences between solutions, while one had mixed results. Six of the sixteen included studies compared differing osmolarities. One found no statistically significant differences between solutions of differing osmolarities, whereas, the remaining five studies found superiority with hyperosmolarity. Two of the sixteen included studies examined the effects of different temperatures. Both studies concluded that the use of a warmer (more physiological) temperature is more ideal. Two of the sixteen studies included in this review compared solutions with differing pH levels. Both studies concluded on the importance of utilizing the more physiological solutions for arthroscopic procedures. Conclusion:Ringer's Lactate and Ringer's Solution as well as non-ionic solutions may have merit over the use of the normal saline for irrigation. Hyperosmolarity, warmer solutions and ones with more physiological pH values may be beneficial when considering potential effects on articular cartilage and chondrocytes. The current review demonstrated trends found in the current literature, which require human studies - preferably high quality RCTs -to make recommendations that aid surgeons in making the best decision regarding the ideal irrigation solution to use on their patients. Level of evidence:Level IV, Systematic review of Level IV studies.

Dataset Information

Influence of fixation on CA4+ contrast enhanced microCT of articular cartilage and subsequent feasibility for histological evaluation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets